In recent years, various methods have been used as a recording method for forming an image based on image data signals on a recording medium such as paper. Among these, an inkjet recording system is an inexpensive apparatus, and since an ink is discharged onto only the necessary image portion to directly form an image on a recording medium, in the inkjet recording system, it is possible to efficiently use the ink, and running cost is low. Furthermore, the inkjet system makes little noise, and therefore, is excellent as an image recording method.
In recent years, in the recording method of the inkjet system, a photocurable ink composition cured by light irradiation has been used as an ink composition which can give good water resistance, solvent resistance, and abrasion resistance.
For example, PTL 1 discloses a photocurable ink composition which includes 2-(vinyloxyethoxy)ethyl acrylate, dipropylene glycol di(meth)acrylate, and a monofunctional (meth)acrylate having an aromatic ring skeleton, and further includes a coloring material, as a polymerizable compound.
For example, PTL 2 discloses a photocurable ink composition obtained by combining 2-(vinyloxyethoxy)ethyl acrylate and at least any one of 1,9-nonanediol diacrylate and 1,10-decanediol diacrylate, as a polymerizable compound.
For example, PTL 3 discloses an active energy ray-curable type inkjet ink composition containing a diacrylate monomer having a linear or branched structure having 10 carbon chains, as a polymerizable compound, and as a specific example, an example in which 2-(vinyloxyethoxy)ethyl acrylate and the diacrylate monomer are used in combination is disclosed.
For example, PTL 4 discloses an ink liquid formed of 2-(vinyloxyethoxy)ethyl acrylate and isobonyl acrylate or 1,6-hexanediol diacrylate, a polymerization initiator, a pigment dispersion, and a surfactant.
For example, PTLs 5, 6, 7, and 8 disclose an ink composition obtained by combining 3-methyl pentanediol diacrylate of a difunctional acrylate monomer and a monofunctional acrylate monomer having N-vinyl caprolactam and a cyclic substituent, as a polymerizable compound.
However, the compositions, inks, or liquids disclosed in PTLs 1 to 8 need to be improved in curing properties and odor generated from the coated film surface after curing.